Electric fuel pump for tank of motor vehicle - has deep recess formed in surface of pumping chamber, preventing frictional loss of rotor speed.

摘要

A relief recess (or clearance) 16b larger in depth than the small gaps between an impeller (1 Fig. 1) and the slide surfaces 16a of a pump casing 16 is formed in the slide surface 16a which is adjacent a pump chamber outlet 6 and radially inward of the pump chamber 4. This arrangement is said to reduce frictional resistance between the pump casing and impeller so that the attendant decrease in the speed of rotation of the motor and increase in power consumption are prevented. IMAGE